Differential pressure control valve



April 23, 1935. F. smuem 1,998,852

DIFFERENTIAL PRESSURE CONTROL VALVE Filed March 16, 1934 2 Sheets-Sheet1 Invenlor n I 5 6% mm was flllorney Aprifi 23, 1935. M o s 1,998,852

DIFFERENTIAL PRESSURE CONTROL VALVE Filed March 16, 1934 2 Sheets-Sheet2 f9 I; Z a 5:5

- 2 z Y f I a. Q IESSUIPE A9 I 40 PI? V 676' P19683095 SIDE /8 sinssarily, adapted for Patented Apr. 23, 1935 oFrcE oneta Ross N ell-LoEENTIAL PRESSE CQNCHEOL VALVE N. Y" assignor of? Application March it,sit, sci-in No. 715,962

This invention relates to an improved differential pressure controlvalve, that is an automatic shut off valve adaptable for installation influid and gaseous conductionlines.

Although the valve is susceptible of general usage in pipe linescarrying different kinds of fluids and mediums, it is especially, butnot necesuse in a refrigerant supply line such as is connected to aconventional or typical compressor constituting apart of a poweractuated refrigeration system, for example of the present day domestictype.

Stated more explicitly, the valve is expressly designed for use on themodern types of commercial and domestic refrigeration units using torest in the crank-case, occasionally causing dangerous leakage of gas.

This vaporized refrigerant gradually condenses in the crank-case, andthe lubricating oil therein, being lighter and floating upon the liquidrefrigerant, is raised to such a'height that it'is thrown upward by thepistons,".and forced through the pistons and exhaust or flapper valvesinto the condensing coils, leaving the crank-case short of lubricant.When placed back in service, a system in which the above conditionexists will invariably motor, unless a restriction is placed on thesuction valve before starting.

As will be hereinafter made evident the principal noveltyis predicatedupon the particular valve, that is the specific construction of saidvalve.

Other features and more readily apparent scription and drawings.

In the drawings:

Figure 1 is an elevational view showing a typical commercial compressordisclosing theimproved safety refrigerant control valve incorporated inthe refrigerant supply line.

Figure 2 is a view, essentially in section, showing the valve per se.

- Fi ure 3 is a horizontal sectional view taken advantages will becomefrom the following deapproximately on, the plane of the line 33 ofFigure 2.

Figure 4 is an enlarged detail sectional and elevational view showingthe valve stem and valve elements detachably connected thereto.

Referring now to Figure 1 of the drawings it will be seen that thecompressor is denoted by fitting 9 and the supply pipe 8.

This valve is detailed in Figure 2 and by, referring to this figure itwill be observed that it one end to provide a tool gripping nut I2, andhaving its upper or top portion iii of circular construction accommodateand facilitate attachment of a structed to-provide an orifice or valveseat l9.

body is formed with a neck 20 removable cap The features 20 and 2| serveprimarily as a hand hole or means permitting had to the valve, valvestem and The-valve stem sioned to the requisite degree as conditionsreof the fitting 9 shown tendant burnt out motors, blown fuses,carbonized systems due to entrance of excess heat. It is simple andeconomical, susceptible of expeditious in the existing or stock parts,simple to adjust and all adjustments are easily accessible. whenproperly adjusted it requires no further: attention throughout the lifeof the unit.

It is understood that although the invention is described asparticularly adaptable for use in a refrigerant circulation line it issusceptible of adequate employment and proper utility in various otherlines requiring the use of a substantially automatically operablecontrol valve.

3|. This regulator matic action and is appropriately attached to thedisk like portion l3 of the body of the valve. It expansible andcontractible and its activity can be regulated through theinstrumentality of the springs 29 which are tenquire.

In practice, the fitting commonly used on suction line valves of presenttype refrigeration units (not shown) is removed and the nipple it of theimproved safety valve H1 is attached to the part in Figure 1. Thesuction line 8 from the cooling coil (not shown) is connected to thenipple I5. A compound gage (not shown) connected to the regular fittingprovided for the same, is then temporarily installed and the pressurecontrol adjusting nuts 28 are adjusted up or down, as the case maybe,until the desired valve shut of! pressure is obtained. The heat ladenvapor passes through the valve in a direction indicated by the arrows,but when the desired pressure on the outlet side i6 is reached, thevalve closes. Obviously the valve closes as a result of pressure exertedwithin the bellows sylphon 3i causing the same to expand and raise thevalve stem 22 to seat or close the valve head 25 against its seat l9.Moreover when the pressure within the bellows is reduced to apredetermined degree the sylphon contracts forcing the valve stem downand opening the valve automatically. Thus, the valve is in a sense anequalizing safety or differential control device. The valve remainsclosed until the operation of the piston reduces the crank case pressurebelow the closing point. No matter what pressure exists on the side l5,pressure on the side l6 can never exceed the amount set for, asimmediately this the safety valve closes. With a zero pressure on theside it, the valve will remain open, ofiering no interference withnormal operating conditions. Thus the valve is automatic in that itdevelops the desired differential or equalizing action on either sidedepending on normal and abnormal pressure conditions.

It has been found that a valve of this type when used in refrigeratingsystems eliminates leaks at the stufling box from excess pressure,overcomes the necessity of placing manual restrictions on units beingput back in service. It reduces gas leaks and loss of refrigerant to aminimum, obviates the necessary of scrubbing oil in so-called warm jobs.It protects the flapper and piston valves against oil hammering,overcomes over loading of the condensing units, with the atto which theinvention relates will be able to obtain a clear understanding of theinvention after considering the description in connection with thedrawings. Therefore, a more lengthy description is regarded asunnecessary.

Minor changes in shape, size, and rearrangement of details coming withinthe field of invention claimed may be resorted to in actual practice, ifdesired.

Having thus claim as new is:

In a refrigerating system, means for automatically closing the pipe lineleading to the com-' pressor when crank case pressure in the compressorbecomes excessive, comprising a valve casing located in the pipe anopening passing through its top and in communication with the lowpressure side of the line,

. a valve seat formed in the casing and opening downwardly into the highpressure side of the casing for placing the opening in communicationwith the high pressure side, a one, piece valve stem passing through thefirst mentioned opening and through the valve seat, a valve having athreaded part threaded to the lower end of the stem and moving upwardlyagainst the seat when moving to closed position, a bellows having itslower end connected with the top of the valve casingand surrounding theupper end of the opening and through the top of which the stem passes,means for connecting the top of the bellows with the stem, a cap-likemember connected described my invention, what I the bellows and having ahole in its top through which the stem passes, a spring encircling apart of the stem and having one end bearing against the top of thebellows and its other end against the top of the cap-like member, asecond spring encircling the outer part of the stem and having one endbearing against the top of the cap-like member and a nut threaded on theupper end of the stem and bearing against the top of the last mentionedspring.

FRANK SIMMONS.

line, said casing having with the top of the valve casing and enclosinginstallation without requiring changes

